Electric potential differences across auroral generator interfaces

Abstract. Strong localized high-altitude auroral electric fields, such as those observed by Cluster, are often associated with magnetospheric interfaces. The type of high-altitude electric field profile (monopolar, bipolar, or more complicated) depends on the properties of the plasmas on either side of the interface, as well as on the total electric potential difference across the structure. The present paper explores the role of this cross-field electric potential difference in the situation where the interface is a tangential discontinuity. A self-consistent Vlasov description is used to determine the equilibrium configuration for different values of the transverse potential difference. A major observation is that there exist limits to the potential difference, beyond which no equilibrium configuration of the interface can be sustained. It is further demonstrated how the plasma densities and temperatures affect the type of electric field profile in the transition, with monopolar electric fields appearing primarily when the temperature contrast is large. These findings strongly support the observed association of monopolar fields with the plasma sheet boundary. The role of shear flow tangent to the interface is also examined.

Download Full-text

On the profile of intense high-altitude auroral electric fields at magnetospheric boundaries

Annales Geophysicae ◽

10.5194/angeo-24-1713-2006 ◽

2006 ◽

Vol 24 (6) ◽

pp. 1713-1723 ◽

Cited By ~ 14

Author(s):

T. Johansson ◽

G. Marklund ◽

T. Karlsson ◽

S. Liléo ◽

P.-A. Lindqvist ◽

...

Keyword(s):

Electric Field ◽

High Altitude ◽

Electric Fields ◽

Plasma Temperature ◽

Plasma Boundary ◽

Cluster Data ◽

Late Evening ◽

Field Lines ◽

Electric Field Profile ◽

Magnetospheric Boundaries

Abstract. The profile of intense high-altitude electric fields on auroral field lines has been studied using Cluster data. A total of 41 events with mapped electric field magnitudes in the range between 0.5–1 V/m were examined, 27 of which were co-located with a plasma boundary, defined by gradients in particle flux, plasma density and plasma temperature. Monopolar electric field profiles were observed in 11 and bipolar electric field profiles in 16 of these boundary-associated electric field events. Of the monopolar fields, all but one occurred at the polar cap boundary in the late evening and midnight sectors, and the electric fields were typically directed equatorward, whereas the bipolar fields all occurred at plasma boundaries clearly within the plasma sheet. These results support the prediction by Marklund et al. (2004), that the electric field profile depends on whether plasma populations, able to support intense field-aligned currents and closure by Pedersen currents, exist on both sides, or one side only, of the boundary.

Download Full-text

Electric-field profile and current control of a long epitaxial GaAs n layer

Electronics Letters ◽

10.1049/el:19720067 ◽

1972 ◽

Vol 8 (4) ◽

pp. 93 ◽

Cited By ~ 1

Author(s):

G.A. Swartz ◽

A. Gonzalez ◽

A. Dreeben

Keyword(s):

Electric Field ◽

Current Control ◽

Field Profile ◽

Epitaxial Gaas ◽

Electric Field Profile

Download Full-text

Elucidating the Influence of Electric Fields toward CO2 Activation on YSZ (111)

Catalysts ◽

10.3390/catal11020271 ◽

2021 ◽

Vol 11 (2) ◽

pp. 271

Author(s):

Nisa Ulumuddin ◽

Fanglin Che ◽

Jung-Il Yang ◽

Su Ha ◽

Jean-Sabin McEwen

Keyword(s):

Electric Field ◽

Electric Fields ◽

Heterogeneous Catalysts ◽

Co2 Reduction ◽

Total Density ◽

Reverse Water Gas Shift ◽

High Thermodynamic Stability ◽

Shift Reaction ◽

Water Gas

Despite its high thermodynamic stability, the presence of a negative electric field is known to facilitate the activation of CO2 through electrostatic effects. To utilize electric fields for a reverse water gas shift reaction, it is critical to elucidate the role of an electric field on a catalyst surface toward activating a CO2 molecule. We conduct a first-principles study to gain an atomic and electronic description of adsorbed CO2 on YSZ (111) surfaces when external electric fields of +1 V/Å, 0 V/Å, and −1 V/Å are applied. We find that the application of an external electric field generally destabilizes oxide bonds, where the direction of the field affects the location of the most favorable oxygen vacancy. The direction of the field also drastically impacts how CO2 adsorbs on the surface. CO2 is bound by physisorption when a +1 V/Å field is applied, a similar interaction as to how it is adsorbed in the absence of a field. This interaction changes to chemisorption when the surface is exposed to a −1 V/Å field value, resulting in the formation of a CO3− complex. The strong interaction is reflected through a direct charge transfer and an orbital splitting within the Olatticep-states. While CO2 remains physisorbed when a +1 V/Å field value is applied, our total density of states analysis indicates that a positive field pulls the charge away from the adsorbate, resulting in a shift of its bonding and antibonding peaks to higher energies, allowing a stronger interaction with YSZ (111). Ultimately, the effect of an electric field toward CO2 adsorption is not negligible, and there is potential in utilizing electric fields to favor the thermodynamics of CO2 reduction on heterogeneous catalysts.

Download Full-text

Plasma-surface interaction: dielectric and metallic targets and their influence on the electric field profile in a kHz AC-driven He plasma jet

Plasma Sources Science and Technology ◽

10.1088/1361-6595/ab0c6a ◽

2019 ◽

Vol 28 (4) ◽

pp. 045003 ◽

Cited By ~ 15

Author(s):

A Sobota ◽

O Guaitella ◽

G B Sretenović ◽

V V Kovačević ◽

E Slikboer ◽

...

Keyword(s):

Electric Field ◽

Plasma Jet ◽

Surface Interaction ◽

Field Profile ◽

Plasma Surface ◽

Electric Field Profile

Download Full-text

Transport parameters and electric field profile in amorphous silicon solar cells

Solar Energy Materials ◽

10.1016/0165-1633(91)90130-d ◽

1991 ◽

Vol 23 (2-4) ◽

pp. 273-281

Author(s):

R. Könenkamp ◽

S. Muramatsu ◽

H. Itoh ◽

S. Matsubara ◽

T. Shimada

Keyword(s):

Solar Cells ◽

Electric Field ◽

Amorphous Silicon ◽

Silicon Solar Cells ◽

Field Profile ◽

Transport Parameters ◽

Electric Field Profile

Download Full-text

Effect of the Electric Field Profile on the Accuracy of E-FISH Measurements in Ionization Waves

Plasma Sources Science and Technology ◽

10.1088/1361-6595/ac4592 ◽

2021 ◽

Author(s):

Tat Loon Chng ◽

David Z. Pai ◽

Olivier Guaitella ◽

Svetlana M Starikovskaia ◽

Anne Bourdon

Keyword(s):

Electric Field ◽

Intermediate Phase ◽

Second Harmonic ◽

Strong Dependence ◽

Field Profile ◽

Test Configuration ◽

True Value ◽

Field Evolution ◽

Electric Field Profile ◽

Fish Signal

Abstract Electric field induced second harmonic (E-FISH) generation has emerged as a versatile tool for measuring absolute electric field strengths in time-varying, non-equilibrium plasmas and gas discharges. Yet recent work has demonstrated that the E-FISH signal, when produced with tightly focused laser beams, exhibits a strong dependence on both the length and shape of the applied electric field profile (along the axis of laser beam propagation). In this paper, we examine the effect of this dependence more meaningfully, by predicting what an E-FISH experiment would measure in a plasma, using 2D axisymmetric numerical fluid simulations as the true value. A pin-plane nanosecond discharge at atmospheric pressure is adopted as the test configuration, and the electric field evolution during the propagation of the ionization wave (IW) is specifically analyzed. We find that the various phases of this evolution (before and up to the front arrival, immediately behind the front and after the connection to the grounded plane) are quite accurately described by three unique electric field profile shapes, each of which produces a different response in the E-FISH signal. As a result, the accuracy of an E-FISH measurement is generally predicted to be comparable in the first and third phases of the IW evolution, and significantly poorer in the second (intermediate) phase. Fortunately, even though the absolute error in the field strength at certain time instants could be large, the overall shape of the field evolution curve is relatively well captured by E-FISH. Guided by the simulation results, we propose a procedure for estimating the error in the initial phase of the IW development, based on the presumption that the starting field profile mirrors that of its corresponding Laplacian conditions before evolving further. We expect that this approach may be readily generalized and applicable to other IW problems or phenomena, thus extending the utility of the E-FISH diagnostic.

Download Full-text